Effect of 8.4% sodium bicarbonate on raised intracranial pressure after traumatic brain injury

Introduction

The aim of this study was to determine the efficacy of 8.4% sodium bicarbonate for intracranial pressure (ICP) reduction in adult patients with severe traumatic brain injury (TBI) and intracranial hypertension.

Methods

The study examined 10 episodes of ICP >20 mmHg in seven patients with severe TBI. Eighty-five milliliters of 8.4% sodium bicarbonate was infused over 30 minutes when osmotherapy was indicated after standard care. ICP, mean arterial pressure (MAP), and cerebral perfusion pressure (CPP) were recorded at baseline and then continuously for 6 hours. Serum pH, pCO₂, (Na⁺), and (Cl^-) were measured at baseline, 30 minutes, 60 minutes and then hourly for 6 hours. Serum osmolality was measured at baseline and at 6 hours in three patients. All other care was identical to the institutional protocol for the management of raised ICP.

Results

At the completion of the infusion, the mean ICP was reduced to 36.2% of baseline, from 28.5 mmHg (±2.62) to 10.33 mmHg (±1.89). Mean ICP remained below 20 mmHg for 6 hours (Figure 1). CPP was increased after the infusion due to the effect on ICP. MAP did not change. Mean pH was elevated at t = 30 minutes (from 7.45 ± 0.02 to 7.50 ± 0.02) and remained elevated for the duration of the study period. Serum (Na⁺) increased (from 145.4 ± 1.9 mOsm/l to 147.1 ± 1.9 mOsm/l) at 30 minutes. pCO₂ did not change. Osmolality was elevated.

Figure 1

Conclusions

Eighty-five milliliters of 8.4% sodium bicarbonate infused over 30 minutes is effective at reducing sustained ICP >20 mmHg to within accepted treatment targets (ICP <20 mmHg) for at least 6 hours.